Stop to! rounding?

[Jonathan M Davis]

On Wednesday, July 03, 2013 07:04:47 cal wrote:
> On Wednesday, 3 July 2013 at 04:32:15 UTC, Jonathan M Davis wrote:
> > On Wednesday, July 03, 2013 06:23:12 Josh wrote:
> >> writeln(to!double("151.42499"));    //prints 151.425
> >> 
> >> Is there any way to stop this rounding?
> > 
> > No. double can't hold the value 151.42499. There are _tons_ of
> > values that it
> > can't hold exactly. The same goes for float and real. Floating
> > point values are
> > rounded all the time. Note that
> > 
> >     double d = 151.42499;
> >     writeln(d);
> > 
> > prints exactly the same thing as your example.
> > 
> > - Jonathan M Davis
> 
> void main()
> {
>     double d = 151.42499;
>     assert(d == 151.42499);
> }
> 
> The rounding occurs in writeln surely.

That's true because _both_ of the floating point values there get rounded to 
151.425, and 151.425 is equal to 151.425. writeln is not doing anything wrong. 
I highly suggest that you read this:

http://docs.oracle.com/cd/E19957-01/806-3568/ncg_goldberg.html

- Jonathan M Davis